9

Camera Tracker: Error Thresholds Rollout 677
>—
Steps forward one frame or keyframe if Step
Keyframesisturnedon.
>10—Steps forward 10 frames, either directly or
one frame at a time if the Master Track Enable
check b ox is turned on.
>>—Stepsforwardtotheendframeoftheselected
tracker, either directly or one frame at a time if the
Master Track Enable check b ox is turned on.
Feature T racki ng—If turned on, any forward steps
w i ll c ause frame-by-frame feature t rack ing to be
performed for all enabled trackers with unknown
position data at the frames you previously stepped
through. You can use this to perform a track ing
checkwhiletestingboundssettingsortoreview
tracked positions one frame at a time. The tracker
also moves the gizmos to previously tracked
positions, so you can review t r acking results
a few frames at a time. If you want, you can
force a retrack by nudging a keyframe gizmo
back-and-forth w hich causes the gizmos to drop
all subsequent tracked positions up to the next
keyframe.
Note: Make sure this button is tur ned off if you just
want to step through the mov ie without tracking,
such as when bro wsing through the movie to
find and place Star t and Stop frames for trackers
that come on screen or go off screen during t he
tracking range.
Cle ar Tra ckin g t o E n d —Removes all tracked
positions and keyfram es from the current stepper
frame onward for the currently selected tracker.
This is often helpful if you have too many errors
and error correcting keyframes at the end of a
track and you want to clear them and tr a ck to the
end again.
Step K eyframes—Modifies the operations of the
single-step buttons in the Movie Stepper. If turned
on, the single step buttons step immediately to
the next or previous keyframes, allowing you
to browse through them quickly. In this mode,
feature tracking is disabled.
Show Track —Displays a visible tracking line in
the Movie window for the currently selected
tracker. This button shows w here the tracker
has currently tracked. A red li ne is displayed for
tracked segments, a white dashed line for segments
stilltobetracked. Whitedotsarecenteredon
each frame position with a green box around each
frame position at which you or the tracker create
keyframes.
Live Camera M atch—Enabled af ter you set up the
match parameters and select a match camera in
the Match rollout. If tur ned on, the match camera
positionisrecomputedandadjustedasyoumove
gizmos in the Movie window . This can be useful
for making corrections to bad match frames by
adjusting the trackers or to check the effect of
tracker placement on the match computations.
This is best done with the nudge arrows. Turn on
the 3ds Max Auto Key button to record adjusted
match camera positions.
Sync Animation—C ontrols whether the scene t ime
slider is advanced in step with the movie fr ames
during stepping. This is sometimes useful if you
have the movie set up as an animated b ackground
image in the match camera window. Check camera
positioning at the same ti me you check feature
positioning. This can slow stepping substantially,
so it’s tur ned off by default.
Camera Track er: Error Thresholds
Rollout
Utilities panel > Utilities rollout > More button > Utilities
dialog > Camera Tracker > Error Thresholds rollout
The Camera Tracker utility’s Error Thresholds
rollout attempts to identify feature tracking errors
by taking measurements and comparing them to
thethresholdsthatyousetupinthisrollout.You